When you upload a tax return to Google Drive or a confidential contract to Dropbox, you are trusting those companies implicitly. They encrypt your files on their servers, but they hold the keys. They can, and sometimes do, scan your files for compliance, advertising profiles, or law enforcement requests.
Client-Side Encryption is the Only Way
If a file is sensitive, it must be encrypted *before* it leaves your device. This is known as client-side encryption.
Tools like Keybase and OnionShare offer excellent secure sharing, but they often require the recipient to install specialized software. This creates friction when sharing with clients, lawyers, or family members.
Frictionless Zero-Knowledge Sharing
Wispr bridges this gap by bringing client-side encryption to the browser.
- You select a file (up to 10MB).
- Your browser encrypts the file locally using AES-256-GCM.
- The encrypted blob is uploaded to Wispr.
- You receive a link with the decryption key embedded in the URL fragment.
When the recipient opens the link, their browser downloads the encrypted blob, extracts the key from the URL, and decrypts the file locally. It is entirely seamless, requires no software installation, and ensures that neither Wispr nor your ISP can read the contents of your file.
For credential sharing rather than file sharing, the same zero-knowledge model applies — see how to share passwords securely. And for the full list of professional scenarios where ephemeral sharing matters, real-world burn-after-reading use cases covers the range from API keys to legal disclosures.
